Preparation of sulphonate-containing core/shell latex particles via seeded emulsion copolymerization

<正>In this study,P(St-MAA) seed latex particles were first prepared via soap-free emulsion polymerization of styrene(St) and methacrylic acid(MAA),then the seed particles were allowed to swell with St at room temperature,and the P(St-MAA)/P(StNaSS) core/shell latex particles were then synthesized via seeded emulsion copolymerization of St and sodium styrene sulphonate (NaSS) using AIBN as initiator in the presence of N,N'-methylenebisacrylamide(BAA,water-soluble crosslinker).Results showed that the polymerization could be carried out smoothly when the ratio of BAA to total monomers was less than 3 mol%,the narrow dispersed P(St-MAA) seed particles with the diameter of 150 nm and the P(St-MAA)/P(St-NaSS) core/shell latexes with the particle size of about 200 nm were synthesized.When the 25/75 mole ratio of NaSS/(St + MAA) and 2 mol%of BAA were used in the seeded emulsion polymerization,the resulted P(St-MAA)/P(St-NaSS) latex product showed a low weight loss after water extraction,and the NaSS unit content in the whole particle and in the shell reached 11.7 mol%and 34.6 mol%,respectively.     

稳态荧光探针法研究复配乳化剂的聚集行为

采用荧光探针技术,根据芘的第一振动峰I₁(373 nm)与第三振动峰I₃(384 nm)荧光强度的比值(I₁/I₃)随乳化剂浓度的变化,对十二烷基磺酸钠(AS)与壬基酚聚氧乙烯醚(Oπ-10)复配乳化剂的CMC值进行了测定,并与十二烷基磺酸钠(AS),壬基酚聚氧乙烯醚(Oπ-10)的CMC值进行了比较,结果表明复配乳化剂的CMC介于两者之间.以二苯甲酮为猝灭剂,用稳态荧光法测定了不同比例复配乳化剂的胶束聚集数,实验结果表明,复配乳化剂浓度为4—9倍CMC时,测定的胶束聚集数随复配乳化剂浓度的增大而线性增大;且Oπ-10:AS<2:1时,随着复合乳化剂中Oπ-10比例的增大,复配乳化剂胶束聚集数增大.利用芘的I₁/I₃值,结合胶束微环境的极性变化规律,探讨了复配乳化剂的聚集行为对硅丙乳液聚合物的影响.     

Observation of paramagnetic triplet species during the thermal polymerization of bis(p-toluene sulphonate) of 2,4-hexadiyne-1,6-diol

ESR observations of single crystals of bis(p-toluene sulphonate) of 2,4-hexadiyne-1,6-diol during solid state thermal polymerization at 60°C reveal spectra characteristic of paramagnetic triplet species. One centre has large values of the fine structure tensor and maximum intensity at maximum polymerization rate. The other has small fine structure values and anneals out slowly after the period of rapid polymerization. The nature of these centres is discussed.     

On the relationship of optical absorption energy and conversion during the polymerization of a crystalline diacetylene

Shifts in the optical absorption energy of polymer chains during polymerization of microcrystalline bis(p-toluene sulphonate) diacetylene are shown to be in accord with changes in the strain imposed on the chains by the mismatch of the monomer and polymer crystal lattices.     

Electric polarization generated by the solid-state polymerization of pTS

Single crystals of pTS (bis-p-toluene sulphonate of 2,4-hexadiyne-1,6-diol), when annealed at 350 K, generate an electrical signal peaking at a time corresponding to that of a maximum polymerization rate. It is shown that a steady-state polarization of the order of 10^?4 C/m² is built into the pTS samples during the polymerization. The effect is probably associated with a non-compensated dipolar species created on polymerizing pTS crystals, and possibly also accounts for the pyroelectricity of poly-pTS.     

Preparation of sulphonate-containing polymer particles <Emphasis Type="Italic">via</Emphasis> semi-continuous emulsion copolymerizaion of styrene and sodium styrene sulphonate

Submicron-sized P(St-NaSS) latexes were prepared via a semi-continuous emulsion copolymerization of styrene (St) and sodium styrene sulphonate(NaSS) in the presence of anionic surfactant,in which NaSS aqueous solution and St were separately dropwise charged into the polymerization system at the same time.The hydrodynamic diameter of the latex particles was measured by dynamic light scattering(DSL) method,and the NaSS unit content of the purified copolymer by water extraction was calculated based on the elementary analysis.Results showed that the copolymerization could be performed smoothly with the monomer conversion more than 96%in the absence of crosslinker,and PNaSS homopolymer could be removed from the latex product by water extraction for 28 h.The weight loss in the water extraction tended to decrease and the NaSS unit content of the purified copolymer tended to increase with the increase of monomer feeding time, and both of them increased with the increase of NaSS/St mole ratio in the charge.The introduction of divinyl benzene (DVB) could decrease the weight loss in the water extraction and increase the NaSS unit content of the purified copolymer. When 25/75 mole ratio of NaSS/St and 11 mol%DVB of total NaSS and St were used in the recipe,and the monomer feeding time was 3 h in copolymerization,the NaSS unit content of the purified copolymer reached 7.31 mol%.     

乙二胺基乙磺酸钠的合成与表征

乙二胺基乙磺酸钠是水性聚氨酯合成中重要的亲水性扩链剂, 又可作为有机中间体、生化试剂应用于其它领域.采用乙二胺(EDA)和2-氯乙磺酸钠反应合成乙二胺基乙磺酸钠, 由红外光谱(FTIR)、核磁氢谱(1H NMR)和碳谱(13C NMR)、X射线衍射(XRD)、元素分析等手段表征了产物的结构与特性. 在EDA与2-氯乙磺酸钠物质的量比为6.5∶1时, 合成产物中乙二胺基乙磺酸钠含量高达94.4%. 产物极易溶于水, 微溶于甲醇, 乙醇, 不溶于丙酮, N,N-二甲基甲酰胺, 四氯化碳, 氯仿等有机溶剂.     

接枝丙烯酰胺共聚物的溶液性能和微结构

采用水溶液自由基聚合法合成了新型的丙烯酰胺(AM)/4-乙烯苄基辛烷基酚聚氧乙烯(18)醚(VE)/2-丙烯酰胺基-2-甲基丙磺酸钠(NaAMPS)接枝共聚物(PAE),以解决驱油聚合物抗高盐性能差的难题.通过傅里叶变换红外(FT-IR)光谱和核磁共振氢谱(1HNMR)对PAE的分子结构进行了表征.PAE盐溶液显示了两次盐增稠和热增稠效应.对于VE摩尔分数为0.93%的PAE,当其质量浓度为2.0g·L-1时,于30℃在5.0和90.0g·L-1NaCl溶液中的表观粘度分别为1167.0和338.0mPa·s,显示了优异的增粘和抗盐能力;并且于85℃在5.0g·L-1NaCl溶液中的表观粘度仍达685.0mPa·s,显示了良好的耐温性能.PAE还具有较好的表、界面活性.扫描电镜(SEM)照片显示,PAE在纯水中形成了独特的缔合结构,而且在盐水溶液中也形成了连续的微结构,这表明在水中伸展的分子链在盐水中的构象仍然较伸展.     

离子对色谱法测定化妆品中的苯酚磺酸锌

建立了离子对色谱测定不同基质化妆品中苯酚磺酸锌的分析方法。水剂类和香波类化妆品用20%乙腈水溶液提取,膏霜类和散粉类用80%乙腈水溶液提取,唇膏类加四氢呋喃并用80%乙腈水溶液提取,提取液离心、过滤处理。以四丁基氢氧化铵为离子对试剂,考察了苯酚磺酸锌在离子对色谱中的保留行为并优化了最佳色谱条件:以Kromasil C18(4.6 mm×250 mm,5μm)色谱柱分离,流动相为5 mmol/L四丁基氢氧化铵+25 mmol/L磷酸二氢钠缓冲溶液(pH 2.5)-乙腈(80∶20),等度洗脱,流速1.0 mL/min,柱温30℃,检测波长230 nm。该方法对苯酚磺酸锌的定量下限为:水剂和香波基质中为24 mg/kg、膏霜和唇膏基质中为120 mg/kg、散粉基质中为60 mg/kg,在0.5～50 mg/L范围内,苯酚磺酸锌的线性关系良好,相关系数为0.999 8。在低、中、高3个加标水平下,苯酚磺酸锌的平均回收率为94%～99%,相对标准偏差为0.57%～3.9%。该方法快速、简便、准确,可用于化妆品中苯酚磺酸锌的测定。     

Suspended Emulsion Copolymerization of Acrylonitrile with Methyl Acrylate: Effects of Reaction Parameters on the Polymerization

Acrylonitrile/methyl acrylate copolymers were synthesized by suspended emulsion polymerization with water as dispersed phase and monomers as continuous phase, potassium peroxydisulphate (KPS) as initiator, Span-80 as emulsifier, and poly(vinyl alcohol) (PVA) as suspending agent. Effects of reaction parameters such as water/monomer mass ratio, concentration of initiator, polymerization temperature and agitation rate on polymerization conversion and the particle size distribution of acrylonitrile/methyl acrylate copolymers were studied. It was found that polymerization conversion increased with an increase of water/monomer mass ratio, concentration of initiator and polymerization temperature, while the agitation rate had no significant effect on the polymerization conversion. Particle size distribution became narrower with an increase of water/monomer mass ratio and agitation rate. Under the same initiator concentration and polymerization temperature, particle size distribution became wider along with polymerization time. The differential scanning calorimetry (DSC) results indicated that the peak temperature of the copolymers decreased with increasing MA content.     

Rheological behavior of an acrylamide-based terpolymer with p-vinylbenzyl-terminated octylphenoxy poly(ethylene oxide)

A comb-like associating terpolymer PAOE was synthesized from acrylamide (AM), sodium 2-aciylamido-2-methylpropane sulphonate (NaAMPS) and a novel macromonomer: p-vinylbenzyl-terminated octylphenoxy poly(ethylene oxide) (VOE, degree of polymerization: 4??using aqueous free-radical copolymerization technique. The polymer chains were still comparatively extended in the brine solutions at low polymer concentrations. This leaded to the formation of continuous network structures via the intermolecular hydrophobic associations of the octylphenyl groups in despite of the addition of NaCl. As a result, PAOE predominantly exhibited significant elastic characters in brine solutions at 0.5?C9 g/dL NaCl, as well as in aqueous solutions. The viscous and elastic character decreased slightly with increasing temperature from 25 to 45°C for the PAOE brine solution with 0.5 g/dL NaCl. The PAOE aqueous and brine solutions displayed obvious shear thickening behavior upon consecutive steady shear cycles. The brine solution also showed the excellent thickening properties, salt-thickening behaviors twice, and resistance to salt.     

The solid-state thermal polymerization of bis(p-toluene sulphonate) of 2,4-hexadiyne-1,6-diol. III. An ESR study

Electron spin resonance (ESR) observations of the solid-state thermal polymerization of bis(p-toluene sulphonate) of 2,4-hexadiyne-1, 6-diol at 60°C, 70°C, and 80°C are reported. The weak paramagnetism observed in polycrystalline samples is interpreted in terms of departures of the polymer chain from an equilibrium conformation. Decomposition occurs at 70°C and 80°C during the final phase of polymerization producing additional paramagnetic centers. Lineshape parameters measured during polymerization show changes which we attribute to changes in the delocalization and mobility of the paramagnetic center. We conclude that the nature of paramagnetism in crystalline conjugated diacetylene polymers is a chain defect property characteristic of interband electronic states close to the valence band.     

茂钛催化剂苯乙烯原位间规聚合制备sPS/蒙脱土纳米复合材料

聚合物基纳米复合材料具有常规有机 /无机复合材料所没有的结构和形态 ,其性能较普通的聚合物复合材料更优异 ,因而引起人们的广泛关注 [1～ 4 ] .近年来的研究表明 ,运用插层聚合和熔融插层等方法可使某些具有层状结构的硅酸盐与聚合物产生特殊的界面作用 ,并以纳米尺寸均匀分     

β-二酮钛非茂催化剂催化降冰片烯聚合

用 (dibenzoylmethanato) 2 Ti(OPh) 2 [(dbm) 2 Ti(OPh) 2 ]/甲基铝氧烷 (MAO)为代表的新型 β 二酮钛非茂催化剂实现了降冰片烯的聚合 ,得到加成聚合和开环易位聚合的混合物 ,研究了实现高聚合活性所需的特殊条件及所得的聚合物结构 ,主要应用傅立叶转变红外技术 (FTIR)对聚合物结构进行了表征和分析     

8-苯胺-1-萘磺酸钛配合物的合成及催化乙烯与降冰片烯共聚合反应

合成了新型催化剂8-苯胺-1-萘磺酸钛配合物, 并应用于乙烯与降冰片烯的共聚合反应中. 分别考察了助催化剂种类[甲基铝氧烷(MAO)和三乙基铝(TEA)]、 降冰片烯浓度、 Al/Ti摩尔比、 聚合温度和聚合压力对催化活性与共聚性能的影响. 通过核磁共振、示差扫描量热和凝胶渗透色谱等对所制备的共聚物进行了表征. 结果表明, 在相同条件下, 以MAO为助催化剂时, 共聚催化活性更高, 催化剂为单活性中心, 可得到分子量分布较窄(PDI≈3)的共聚产物, 其共聚反应机理为加成聚合. 另外, 随着降冰片烯浓度的升高, 共聚物中降冰片烯单元的摩尔比呈线性上升趋势, 所得共聚物的熔点随之降低.     

AN/St悬浮共聚体系中AN在水/油两相间分配及其对共聚物组成的影响

研究了丙烯腈/苯乙烯(AN/St)悬浮共聚体系中AN在水/油两相间的分配及其对AN/St共聚物组成的影响.结果表明,AN分配于水/油两相间,使油相AN的含量低于相同单体配料比的本体聚合,导致生成的AN/St共聚物组成偏离本体共聚.为了准确预测进而控制AN/St悬浮共聚物的组成,提出了在考虑AN相分配的基础上计算AN/St悬浮共聚物组成的模型.计算结果与实验值一致,计算中用到的油相实际竞聚率与本体聚合相同,但该悬浮聚合的表观竞聚率随水/油比的变化而发生较大改变.     

单茂钛催化剂催化丁烯-1聚合及高分子量无规聚丁烯-1的合成与表征

Kaminsky等 [1,2 ] 用二茂基 ( Cp,Ind,Flu)过渡金属 ( Ti,Zr和 Hf)化合物 /MAO催化剂催化丁烯 - 1聚合 ,得到间规 -等规或间规 -等规 -无规的混合物 ,聚合物的分子量为 5 0 0 0 0至 1 5 0 0 0 0 .Rossi[3] 用( CH3) 2 Si( H4 Ind) 2 Zr Cl2 /MAO研究了丁烯 - 1的等规聚合 ,产物分子量仅 2 0 0 0左右 .林尚安等[4 ,5] 采用单茂钛催化剂 Cp* Ti( OBz) 3/MAO催化丁烯 - 1聚合 ,产物为立体多嵌段聚丁烯 - 1 .但目前尚未见到有关采用茂金属催化剂催化丁烯 - 1聚合制备高分子量无规弹性体聚丁烯 - 1的报道 .我们用单茂钛 Cp* Ti( OC…     

Kinetic studies on the syndiotactic propylene polymerization catalyzed over iPr(Cp)(Flu)ZrCl2

Kinetic studies on the syndiospecific polymerizations of propylene with iPr(Cp)(Flu)ZrCl₂/methylaluminoxane (MAO) were performed at 20, 40 and 70 °C and at 5 atm with various Al/Zr molar ratios. The average polymerization activity for 60 min decreased, and the time to reach a maximum activity (t_max) decreased as Al/Zr molar ratio increased. However, at Al/Zr molar ratio of 10,000, catalytic activity decreased rapidly and became the smallest among any other Al/Zr molar ratios after 20 min of polymerization. At higher Al/Zr molar ratio, methylation and cationization progress rapidly, but its polymerization rate decayed quickly due to strong interaction between MAO and metallocene, resulting in less active species. Regardless of change in polymerization temperature, t_max was maintained around 15 min. Stereoregularity was strongly dependent on the polymerization temperature, and active site isomerization was dominant source for stereoirregularity, and it was strongly influenced by polymerization temperature.     

RING-OPENING POLYMERIZATION OF TRIMETHYLENE CARBONATE BY CALIX[8]ARENE-NEODYMIUM*

Ring-opening polymerization of trimethylene carbonate (TMC) with a rare earth calixarene compound as catalysthas been studied for the first time. The effect of TMC/Nd (molar ratio) and polymerization conditions were investigated indetail. It was found that calix[8]arene-neodymium is a highly effective catalyst for the bulk polymerization of TMC and giveshigh molecular weight (M_v = 60,000) polymer. The optimum conditions of TMC polymerization were found to be asfollows:TMC/Nd (molar ratio) = 2,000, 80℃, 16 h. The polymers were characterized by NMR, GPC and DSC. Studying themechanism by NMR showed that the polymerization of TMC catalyzed by calix[8]arene-neodymium proceeds via a cationicmechanism.     

(n-BuCp)_2TiCl_2/Sn/I_s引发合成梳形羟基功能化无规聚苯乙烯及聚合物结构与性能的研究

采用茂金属化合物(n-BuCp)2TiCl2,还原剂(Sn),引发剂苯基缩水甘油基醚甲醛共聚物(Is)组成的催化体系引发苯乙烯活性自由基聚合,合成梳形羟基功能化无规聚苯乙烯.考察了聚合温度、聚合时间及引发剂与单体的比例对苯乙烯聚合的影响.当聚合温度在65～95℃范围内,随着聚合温度的升高,聚合物的分子量及单体转化率增加;在一定温度下,聚合物的分子量与单体转化率之间存在线性增长关系,且聚合物的分子量分布较窄(Mw/Mn=1.6～1.9).采用GPC,WAXD,13C(1H)-NMR对聚合物(沸丁酮可溶级分)的结构与性能进行了表征.GPC结果证明(n-BuCp)2TiCl2/Sn/Is引发苯乙烯聚合为活性聚合;13C-NMR和WAXD结果说明聚苯乙烯链段为无规结构;1H-NMR结果表明聚合物分子链中含有羟基,并根据其结果计算出聚合物分子的臂数为4,与引发剂Is的环氧基团数相等.这些结果证明了其聚合机理是经环氧基团开环后形成的自由基引发苯乙烯自由基聚合.